Filter



R. A. BUB

FILTER July 23, 1957 INVENTOR.4 /eeer i E2/a .lill n IIIFLIEJTLMIHMHL United States Patent O FILTER Robert A. Bub, Penn Township, Pa., assignery to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Application February 2.8, 1955, Serial No. 491,016

6 Claims. (Cl. 183-71) This invention relates to filtersfor gases and vapors, and more particularly to the manner of sealing such filters.

It is among the objects of this invention to provide a filter which can be made from one piece of filtering material, which is securely sealed along its opposite sides, which is folded and sealed simultaneously, and which opcrates satisfactorily whether fiuid flows through it in one direction or the opposite direction. Y

In accordance with this invention, a` strip of filtering material is folded -transversely upon itself at longitudinally spaced intervals to provide .a plurality of parallel depending pockets spaced at their upper ends by narrow connecting areas. The opposite sides of each pocket, at each end of it, are sealed together, preferably with the aid of an adhesive. Vertical spacing blocks are located between the sealed ends of adjacent pockets in tight engagement therewith beneath the connecting areas. The pockets are held open by separators, While other separators may be located between the pockets. The outer surfaces of the end pockets have end plates beside them, and a binding member surrounds the pockets and plates and holds the spacing blocks and the ends of the pockets tightly together. rl`he filter may be mounted in a receptacle having an open top that is surrounded by a flange. A thin gasket member or face overlies the flange and the areas of the filter strip above the blocks and is cemented to those areas. A gasket is pressed against the gasket face above the flange.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

Fig. l is a plan view of my filter, with parts broken away to show underlying parts, some in section;

Fig. 2 is a side view and Vertical section, taken on the line Il of Fig. l; and

Fig. 3 is a fragmentary horizontal section taken on the line lll-III of Fig. 2.

Referring to the drawings, a single strip of filtering material, such as any suitable lter cloth or paper, is provided at spaced intervals with pairs of parallel transverse folds. Assuming for the sake of description that the strip is horizontal when it is folded, the material between the pairs of folds hangs down in loops. The opposite ends of the side walls 1 of each loop are sealed together to form a pocket that is open at the top. The sealing is done with the help of an adhesive, which is applied to the margins of the filter strip just before it is folded.

In making up the filter, the strip of filtering material is folded to provide one pocket at a time. As soon as the ends of a pocket have been sealed, spacing blocks 2 are placed against the double thickness ends and then the next pocket is formed in the same way on the opposite side of those blocks and pressed against them. Each block extends from the narrow connecting area of the filter material at its top down to at least the bottom of the adjoining pockets. As each pocket is formed,

Patented July 2 3, 1957 Z a pair of these spacing blocks are placed yagainst its ends. The blocks press the adhesive surfaces together as the filter is being formed. The outersurfaces of the two end pockets have rectangular end plates 3 beside them,

and the ends 4 of the filter strip overlie the top surfaces of these plates. The end plates preferably are spaced from the sealed ends of the end pockets by spacing blocks 5 that are about half as thick as those that space the ends of the pockets from one another. The bundle of blocks, end plates` and filtering material then is bound tightly together by a suitable binding member 6 surrounding the unit. For example, glass tape may be used for this purpose, with its ends cemented together. The blocks not only space the ends of the pockets apart, but'their pressure against the pockets insures that thoseends will not open up andleak. 4 l

As the filter is assembled, a very thin and flexible sealing member 7, called a Vgasket face, is cemented to the areas of the filtering material overlying the upper ends of the blocks and to the top of ends 4 of the strip. The

K adhesive which was applied to the marginsof the filter strip can be used to hold the gasket face. The gasket face extends out beyond the ends of the pockets for a purpose that will be described presently.

To hold the pockets open sothat fluid can enter or leave them, separators 11 are insertedin them. Preferably, theseparators are pleated orvcorrugated sheets, with the ridges extending vertically. This permits fluid to enter or leave the pockets through the Vertical channels in the separators. Fluid can flow in either direction through the filter, because additional separators 12 are inserted between the pockets to hold them apart when the flow is downward. The separators project vertically from the pockets to help protect the filtering strip from abrasion and other damage during fabrication and use of the filter. For the same reason, the spacing blocks and en-d plates 4also extend below the bottom of the pockets.

Although the filtering strip may be made of any suitable material, it is preferred to use mineral fibers such as glass, asbestos, and fiber frax, separately or combined. Such material makes a very good filter, and it also can withstand high temperatures and has other advantages, such as chemical resistance and lightness in weight. The spacing blocks, end plates and gasket face may be made of similar material.

The filter unit formed in the manner just described can be used as it is, or be inserted in a suitable container or pot 13 which has its open upper end surrounded by an integral fiange 14. The bottom of the pot may be provided with .a large number of holes 15 to permit fluid to enter or leave. The pot preferably is made of material similar to the filter strip. The ends 4 of the strip extend out beyond the end plates and over the ange of the pot. The laterally projecting areas of the gasket face 7 also extend over the pot flange.' A gasket 15, which may be made of the same kind of material as the pot, is applied to the upper surface of the gasket face above the pot flange. Filter strip ends 4 and the projecting areas of the gasket face seal the narrow spaces between the filter unit and the sides of the pot when thegasket is pressed tightly against the gasket face.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

l claim:

l. A filter comprising a strip of filtering material folded transverselyppon itself at longitudinally spaced intervals to provide a plurality of parallel depending pockets spaced at their upper ends by narrow connecting areas, the opposite' sides-of Veachfpocket a't each zend. thereof being sealed together,V vertical spacing blocks between the sealed ends .of .adjaeent pockets `in tight ,engagement therewith beneathusaid connecting areas, said blocks extending substantially from top to bottom of the pockets, and means in said pockets holding them open.

2. A lter according to claim Vl, including a thin gasket face cemented to the top :ot'jsaid strip above said blocks and extending outward therefrom.

3, A filter comprising a strip of filtering material folded transversely upon itself at longitudinally spaced intervals to provide a plurality ofparallel depending pockets spaced at theirupperendsy by narrow connecting areas, Athe opposite sides of eachpocket 'at each end thereof being sealed together, verticalfspacing blocks between the sealed ends of adjacent pockets in tight engagement therewith beneath .said connecting areasLfa binding member surrounding` said pockets and holding said blocks and the ends of the pockets ytightly together, and means in said pockets holding them open.

4. A lilter according ,toV claim l, including end plates beside the outer surfaces ofthe end pockets, the ends of said strip overlying the top surfaces of said plates, and a thin gasket face cemented -to the tops of said overlying ends and tothe t'op of said strip above said blocks, the gasket face extending Aoutward from said blocks.

5. A filter comprising a strip of ltering material folded transversely upon :itself at longitudinally spaced intervals to provide a plurality of parallel depending pockets spaced at their upper ends by narrow connecting areas, the opposite sides of each pocket at each end thereof being sealed together, vertical spacing blocks between the sealed ends of adjacent pockets beneath said connecting areas, end plates beside the outer surfaces of the end pockets, the ends of said strip overlying the top surfaces of said plates, separating means `in said pockets and between the pockets to hold the pockets open and spread apart, and a ibinding member surrounding said plates and blocks and holding them andthe ends of the pockets tightly together.

6. A filter according vto claim l, including a pot containing said blocks and folded strip and having an open top surrounded by a flange, the lends of said strip overlying said ange at opposite sides of the pot, a gasket face cemented to the tops of said strip ends and to the top Vof said strip `above said blocks, the gasket face extending outward beyond said blocks and over said iiange, and a gasket bearing against the top of the said gasket face to press it against V'said flange all around the pot.

Referenees Cited -in the -tile of this patent s 'UNITED STAT-Es rA'rENTs 930,561 

